Assembly for clutches or brakes



Oct. 14, 1947.

T. L. FAWICK ASSBIBLY FOR CLUTCHES 0R BRAKES Filed nach 19, 1945 INVENTOR THaMA FAW/CK ArroRNEY Patented Oct. 14, 1947 UNITED sTATEs aATENT OFFICE ASSEMBLY Fonzclms oa BRAKES i AppcaranmbifcblrllllcSxelizl? 583,532

(c1. lss- 152) 4 Claims. 1

This invention relates to fluid-actuated assemblies suitable for use as clutches or brakes.

Its chief objects are to provide an assembly comprising improved means for assuring prompt and complete disengagement of the clutch or brake upon the venting of pressure fluid from a fluid-distensible actuatingmember; and to provide simplicity and economy of construction and facility of assembly, disassembly and repair.

Of the accompanying drawings:

Fig. 1 is a fragmentary elevation of an assembly embodying my invention in its preferred form.

Fig. 2 is a section on line 2--2 of Fig. 1.

Fig. 3 is a section on line3-3 of Fig. 1.-

Referring to the drawings, the specific embodiment here shown comprises a drum I having an outer surface adapted to be trictionally engaged by a circumferential series of wear-shoes II of suitable brake-lining material, each of which is secured, as by vulcanization, to a metal baseplate I2.

The mounting for these wear-shoe assemblies comprises an annular, but permissibly sectional, inwardly open channel member I3 of sheet metal in the channel of which is mounted an annular, but permissibly sectional, fIuid-distensible bag I4 of cord-reinforced rubber having means (not shown) for conducting distending fluid into it to cause it to distend radially inward, to force the wear-shoes I I into engagement with the drum I0, and out oi" it to permit'the wear-shoes to be retracted from the drum.

Each of the base plates l2 is formed at each oi' its ends with oppositely projecting stop-lug portions 92a, I2a adapted to come against the stop-face edges of the side flanges of the channel member I3, to limit the outward movement of the wear-shoes.

Also, at its middle, each base plate l2 is formed with a pair of oppositely projecting lugs lib. 12b, to the outer face oi' each of which is secured, as by welding, a spring-engaging eye or hook member lll,` in which is engaged the end portion of a spring I8 which constantly urges the base plate and its wear-shoe outwardly.

The springs IS are mounted in pairs on the outer faces of the side flanges of the channel member I3. where they are readily accessible, the lugs I2b of the base plates, with their hook members I5, projecting outward through respective outwardly tapered notches I1, I'I formed in the inner margins of the said side flanges, and each spring I6 being anchored at its middle by being engaged in a hook I8 formed by stamping and bending a part of the side iiange of the sheet- 2 metal channel member, as clearly shown in Fig. 2. Each pair of springs, opposite each other on the outer faces of the channel` member I3. engages the hooks I5 of two adjacent base plates, so that one pair of springs serves for two4 of the wear-shoes. long range action without high maximum strain, the springs are of the loop type as shown.

The wear-shoes II or base plates I2 do not re-y quire to be secured to the distensible member Il since the springs I6 .provide for their retraction and since the torque is sustained by metal-tometal contact of the lugs I2b in the notches I1 of the channel members side flanges.

When the notches I'I are outwardly tapered as shown, there is some self-energizing effect in the engagement of the clutch or brake, which, according to the degree of taper, can be only sulcient to partially or wholly oiset frictional resistance oi' the lugs I2b, or can be of greater magnitude.

Preferably, for economy, the channel member I3 is made as two annular sections which are joined together by welding. the weld seam being shown atv I9, Figs. 2 and 3, which permits both of the sections to be made by the same simple and inexpensive die equipment.

The channel member I3 can be provided with a relatively heavy backing member or members such as the member 20 on itsl outer face for lstrengthening it and for mounting it.

An advantage of the structure as described, having the channel member I3 formed of sheet metal, is that the actuating assembly is of small radial dimension, for compactness and economy of space.

Another advantage is that when the distensible .bag is vented and the outward movement of the shoes is stopped by the lugs I2a the bag withdraws slightly from the base plates I2, providing an air space as shown for cooling effect.

When the construction' is as shown, with the notches I1 symmetrically tapered in the direction of the disengaging movement of the shoes, the self-energizing eilect is present regardless of which is the driving and which the driven structure and in either direction of drive. As the lug I2b moves inward or outward in contact with a wall of its notch I'I, a slight relative circumferential movement occurs between the shoe and its mounting I3, and this is permitted by slidability of the spring I6 in the hook member IB.

The invention also provides the advantages that are set out in the above statement of objects and modications are possible without sacrifice o! Preferably, for low-modulus,

all of those advantages and without departure from the scope of the appended claims, which, for example, do not Wholly limit the invention to an inwardly engaging assembly.

I claim:

1. An assembly comprising two'relatively rotatable structures adapted for frictional engagement with each other, one of the same having an annular frictional-engagement surface and the other comprising a circumferential series of wearshoe structures for engagement with said surface, a fluid distensible member for moving them into such engagement, a channel shaped member constituting a mounting for said fluid-distensible member, and having opposite side flanges denning the channel, and loop-type cantilever springs mounted on the axially outer sides of the sideflanges and engaged with the wear-shoe structures for retracting them from said surface upon venting of the fluid-distensible member, each of the springs being anchored to the adjacent sidefiange and having its loop so arranged between its point of such anchorage and its point of engagement with a wear-shoe as to yield in a direction transverse to the retracting movement of the wear-shoe.

2. An assembly comprising two relatively rotatable structures adapted for frictional'enga'gement with each other, one of the same having an annular frictional-engagement surface and the other comprising a circumferential series of wear-shoe structures for engagement with said surface, a fluid distensible member for moving them into such engagement, a channel shaped member constituting amounting for said fluiddistensible member and having opposite side flanges defining the channel, and a circumferential serles of loop-type cantilever springs mounted on the axially outer side of, and anchored to, each of the side flanges and engaged with the wear-shoe structures for retracting them from said surface upon venting of the uid-distensible' member, each of the springs being anchored at its middle to the flange of the channel shaped member and at each side of its anchorage being formed with a loop of at least one full turn and with a cantilever arm in extension from the loop.

3. An assembly comprising two relatively rotatable structures adapted for frictional engage,- ment with each other, one of the same having an vannular frictional-engagement 'surface and the other comprising acircumferential series .of wearfshoe structures. for engagement with said `4y surface, a fluid-distensible them into such engagement, a channel shaped member constituting a mounting for said fluiddistensible member and having opposite side flanges defining the channel, and a circumferential series of cantilever springs mounted on the axially outer side of, and anchored to, each of the side flanges and engaged with the wear-shoe structures for retracting them from said surface upon venting of the fluid-distensible member, the springs being radially interlocked with the respective wear-shoe structures but circumferentially slidable with relation thereto, the wear-shoe structures being interlocked with the side flanges for sustension of torque but movable radially with relation thereto, and at least one of the interlocking faces of each pair being so non-radially disposed as to provide a self-energizing effect in the frictional engagement of the two structures.

4. An assembly comprising two relatively rotatable structures adapted for frictional engagement with each other, one of the same having an annular frictional-engagement surface and the other comprising a circumferential series of wear-shoe structures for engagement with said surface, a fluid-distensible member for moving them into such engagement, a channel shaped memberv constituting a mounting for said fluiddistensible Amember and having opposite side flanges defining the channel, and springs mounted on the axially outer sides of the side-anges `and engaged with the wear-shoe structures for retracting them from said surface upon venting of the fluid-distensible member, the wear-shoe structures being interlocked with the side flanges for sustension of torque -but movable radially with relation thereto, by reason ofy each wear-shoe structure' comprising a transversely flat metal base-plate having lateral projections in at least substantially rectilinear extension thereof which extend into recesses formed in the side flanges. THOMAS L. FAWICK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,185,250 Frank Jan. 2, 1940 2,205,521' Fawlck June 25, 1940 2,246,979. Kraft et al. June 24, 1941 1,936,899 Bendix Nov. 28, 1933 2,349,494 Fawick May 23, 1944 member for moving 

